What is connected to the pins you are reading from? If there are switches, do you have the required external pull-down resistors? It's clear from the code that you aren't using the internal pull-up resistors or external pull-up resistors. That leaves only two choices - external pull-down or none. And none won't work.

The digitalRead() function does not take two arguments, so it seems highly unlikely that the first code snippet with digitalRead() actually compiled.

(untested code)if ((digitalRead(Green) == HIGH) || (digitalRead(Yellow) == HIGH)) { digitalWrite(Red2, HIGH);} else { digitalWrite(Red2, LOW);}This tests both Green and Yellow, and if either of them is HIGH, it will light up Red2 as well. And in your case, you will end up with either Green and Red2 or Yellow and Red2, or all three sitting HIGH at some point. Red2 will never go LOW unless you bring both Green and Yellow LOW as well.

So much easier than using else if, and probably will give me less problems

That's the problem with selflearning, you might not come across something like that :/

Thanks dude <3

(as a side note: I originally had the braces but after trying four or five different ways some of my code had them, some of it didn't, and some of them were in just the wrong place so rather than fix it before copying to the forums, I removed them, because functionally it's the same code with or without (obviously there are times where it's necessary)

I recommend ALWAYS using braces on if statements. It's a big help in not shooting yourself in the foot, and is part of many "official" coding standards. (a "coding standard" is the list of things you should do in the code you write that are beyond the requirements of the language itself. For even moderate sized companies, it is important that the multiple people writing code remain consistent with one another, in addition to any real or perceived technical advantages of a particular style. This will cover how identifiers are capitalized, the amount of indentation to use and where it goes, when (if ever) you can omit braces, and a bunch of other stuff.)